Hard as a rock stomach

I will be 29 weeks tomorrow, I was put on bed rest at 23 weeks because I was dilated to 1 already, last week I went to the dr still at 1 1/2 but now I'm thinning. All day today my stomach has been rock hard and vary uncomfortable my other two pregnancies were vary different from this one, so I'm just wondering if anyone else had this hard as a rock belly or no??